Unbound < 1.4.4 Unbound Signed Zone Query Response DNSSEC Outage DoS

Medium Nessus Plugin ID 55048

New! Vulnerability Priority Rating (VPR)

Tenable calculates a dynamic VPR for every vulnerability. VPR combines vulnerability information with threat intelligence and machine learning algorithms to predict which vulnerabilities are most likely to be exploited in attacks. Read more about what VPR is and how it's different from CVSS.

VPR Score: 3.4


The remote name server is affected by a denial of service vulnerability.


According to its self-reported version number, the remote Unbound DNS resolver is affected by a denial of service vulnerability due to a failure to send responses for signed zones after mishandling an unspecified query. An attacker can exploit this, via a crafted query, to cause a DNSSEC outage, resulting in a denial of service condition.

Note that Nessus has not tested for this issue but has instead relied only on the application's self-reported version number.


Upgrade to Unbound version 1.4.4 or later.

Plugin Details

Severity: Medium

ID: 55048

File Name: unbound_1_4_4.nasl

Version: 1.6

Type: remote

Family: DNS

Published: 2011/06/10

Updated: 2018/08/06

Dependencies: 87872

Configuration: Enable paranoid mode

Risk Information

Risk Factor: Medium

VPR Score: 3.4

CVSS v2.0

Base Score: 5

Temporal Score: 3.7

Vector: CVSS2#AV:N/AC:L/Au:N/C:N/I:N/A:P

Temporal Vector: CVSS2#E:U/RL:OF/RC:C

Vulnerability Information

CPE: cpe:/a:unbound:unbound

Required KB Items: unbound/version, Settings/ParanoidReport

Exploit Available: false

Exploit Ease: No known exploits are available

Patch Publication Date: 2010/04/22

Vulnerability Publication Date: 2011/05/27

Reference Information

CVE: CVE-2009-4008

BID: 48209